The present invention concerns an educational aid which facilitates the calculation of equivalent values.
The object of the invention is to make it easily possible to indicate exactly in writing a measurement of the decimal metric system for indicating the dimensions of digits and for the rapid transformation of one measurement into an equivalent one.
As will be clearly explained hereinafter, this educational aid facilitates the learning of the decimal metric system, since it visualises the dimensions of digits.
The educational aid, hereinafter called a "rule", enables a child, by means of its use, to record the value of the symbols and the serial arrangements thereof within the field of comparison in an almost play-like form.
The present invention will be described with reference to the decimal metric system having a base of ten, but it may also be applied to other metric systems having a base different from 10.
Other objects of the present invention will become apparent in the course of the following description, to be taken into consideration, together with the attached sheet of drawings, in which some preferred embodiments of the invention are shown.